EXPLAINER: Why fear of 5G halting flights has faded

The rollout of new 5G wireless service in the U.S. failed to have the much-dreaded result of crippling air travel, although it began in rocky fashion, with international airlines canceling some flights to the U.S. and spotty problems showing up on domestic flights.

Airline industry officials say the decision by AT&T and Verizon — under pressure from the White House — to delay activating 5G towers near many airports has defused the situation.

The delay is giving the Federal Aviation Administration more time to clear more planes to operate freely around 5G networks. On Thursday, the FAA said it had granted new approvals that will allow an estimated 78% of the U.S. airline fleet to make landings even under low-visibility conditions at airports where the new, faster wireless service has been turned on.

That still leaves about one-fifth of the fleet vulnerable to being prevented from landing at some airports during bad weather, but that chunk is certain to shrink. The CEOs of American and United say they don’t expect any major disruptions to flights.

Here is a rundown of what happened.

WHAT'S THE CONCERN ALL ABOUT?

Cellphone companies have been rolling out next-generation 5G service for a few years, and this latest slice of it, the so-called C-Band, helps make AT&T and Verizon more competitive with T-Mobile. It promises faster and more stable wireless networks. But 5G is still mostly promise and less actual applications. For now, it lets you download a movie much faster. But the telecommunications industry is touting it as critical for autonomous vehicles, modern manufacturing, smart cities, telehealth and other fields that would rely on a universe of internet-connected devices.

The concern comes from the fact that this latest bit of 5G operates on part of the...